Impact of body mass index on real-world outcomes of rivaroxaban treatment in Japanese patients with non-valvular atrial fibrillation

Comparative Effectiveness and Safety of Direct Oral Anticoagulants in Low Body Weight Patients with Atrial Fibrillation: A Systematic Review and Meta-analysis

INTRODUCTION

Direct oral anticoagulant (DOAC) agents are established as the anticoagulation strategy of choice for a variety of clinical risks. Despite this, uncertainty still exists with regard to their efficacy and safety for the prevention of stroke and systemic embolism in some patient populations; most notably those with low body weight (LBW) (<60 kg or body mass index [BMI] <18 kg/m2). Currently, there is a paucity of trial and non-trial data to support a prescriptive recommendation for their use in these patient cohorts. We have carried out a pooled systematic review of the most up to date published data of patients stabilized on various DOAC analogs with the view to ascertaining the exact matrices of their efficacy and safety in these cohorts of patients.

METHODS

We initially carried out a comprehensive search of databases from inception to June 2023 for eligible studies exploring the efficacy and safety of various analogs of direct oral anticoagulants in patients with atrial fibrillation who had low body weight. Databases accessed include PubMed, EMBASE, the Science Citation Index, the Cochrane Database of Systematic Reviews, and the Database of Abstracts of Reviews of Effectiveness. We carried out a weighted comparison of derived pooled odd ratios (with their corresponding confidence intervals) of mortality outcomes between various DOACs using the random effects model.

RESULTS

Thirteen studies (n = 165,205 patients) were included in our meta-analysis. DOAC analogs were associated with increased stroke-related events, composite outcome, and mortality in low body weight patients compared to non-low body weight patients (odds ratio [OR] 1.50, 95% confidence interval [CI] 1.17-1.92), (OR 1.55, 95% CI 1.29-1.86), (OR 2.92, 95% CI 1.87-4.58), respectively. There was no significant difference in the safety outcome (major bleeding events) between the DOAC analogs (OR 1.19, 95% CI 0.93-1.52).

DISCUSSION

In this meta-analytical review comprising both real-world and randomized controlled studies, the use of DOAC analogs in low body weight patients (body weight of <60 kg or BMI<18 kg/m2) with atrial fibrillation was associated with increased risks of stroke-related events, composite outcomes, and mortality compared to non-low body weight cohorts patients. At the same time, there was no significant difference in terms of major bleeding events. This finding has provided the first resolution of pervading uncertainty surrounding the use of DOAC analogs in these patient cohorts and suggests the need for follow-up confirmatory systematic studies in this group of patients.

Associations between body mass index and all-cause mortality: A systematic review and meta-analysis

Fasting insulin and c-reactive protein confound the association between mortality and body mass index. An increase in fat mass may mediate the associations between hyperinsulinemia, hyperinflammation, and mortality. The objective of this study was to describe the "average" associations between body mass index and the risk of mortality and to explore how adjusting for fasting insulin and markers of inflammation might modify the association of BMI with mortality. MEDLINE and EMBASE were searched for studies published in 2020. Studies with adult participants where BMI and vital status was assessed were included. BMI was required to be categorized into groups or parametrized as non-first order polynomials or splines. All-cause mortality was regressed against mean BMI squared within seven broad clinical populations. Study was modeled as a random intercept. β coefficients and 95% confidence intervals are reported along with estimates of mortality risk by BMIs of 20, 30, and 40 kg/m2 . Bubble plots with regression lines are drawn, showing the associations between mortality and BMI. Splines results were summarized. There were 154 included studies with 6,685,979 participants. Only five (3.2%) studies adjusted for a marker of inflammation, and no studies adjusted for fasting insulin. There were significant associations between higher BMIs and lower mortality risk in cardiovascular (unadjusted β -0.829 [95% CI -1.313, -0.345] and adjusted β -0.746 [95% CI -1.471, -0.021]), Covid-19 (unadjusted β -0.333 [95% CI -0.650, -0.015]), critically ill (adjusted β -0.550 [95% CI -1.091, -0.010]), and surgical (unadjusted β -0.415 [95% CI -0.824, -0.006]) populations. The associations for general, cancer, and non-communicable disease populations were not significant. Heterogeneity was very large (I2  ≥ 97%). The role of obesity as a driver of excess mortality should be critically re-examined, in parallel with increased efforts to determine the harms of hyperinsulinemia and chronic inflammation.

Association between body mass index and long-term clinical outcomes in patients with non-valvular atrial fibrillation taking oral anticoagulants

BACKGROUND AND AIMS

The association between body mass index (BMI) and clinical outcomes of patients with non-valvular atrial fibrillation (NVAF) taking oral anticoagulants (OACs) are controversial, and we thus analyzed the large registry data to elucidate them.

METHODS AND RESULTS

We conducted a historical cohort study at 71 centers in Japan and included outpatients with NVAF taking vitamin K antagonists (VKAs). Physicians in charge could change VKAs to direct OACs based on their judgement during follow-up period. We categorized patients into four BMI groups (kg/m²): underweight (BMI < 18.5), normal weight (18.5 ≤ BMI < 25), overweight (25 ≤ BMI < 30), and obese (30 ≤ BMI). The effects of each BMI group relative to the normal weight group on clinical outcomes consisting of all-cause death, ischemic events, and bleeding events were estimated using Cox proportional hazard models adjusting for potential confounders. We also constructed restricted cubic spline regression model adjusted by multivariable Cox proportional hazard models. We included 6927 patients consisting of an underweight (n = 386), normal weight (n = 3785), overweight (n = 2174), and obese (n = 582) groups. The median follow-up period was 3.9 years. In the underweight group, the adjusted hazard ratios (HRs) for all-cause death and ischemic events were 1.75 (1.30-2.34) and 1.61 (1.04-2.50). The HR for all-cause death was 0.63 (0.49-0.82) in the overweight group. Restricted cubic spline regression models confirmed that lower BMI showed significantly higher risks for all-cause death and ischemic events.

CONCLUSION

Among NVAF patients taking OACs, underweight patients had higher risks of all-cause death and ischemic events than other patients. Overweight patients had lower risk of all-cause death.

Safety and efficacy of direct oral anticoagulants in comparison with warfarin across different BMI ranges: A systematic review and meta-analysis

Background

Many publications have compared various outcomes defining safety and efficacy of DOACs across different BMI ranges. Our meta-analysis compares warfarin and DOACs for its treatment effects over different BMI ranges.

Methods

A systematic search was conducted from inception to May 2021 on PubMed, Scopus and Embase databases. The data was extracted and pooled using a random effects model. Our study consisted of patients being treated for VTE and AF, across different BMI categories. For the comparison of DOAC, risk ratios (RR) with 95% confidence intervals (CIs) were used, whilst for the second comparison between warfarin and DOACs odds ratios (OR) were used.

Results

In our first comparison, 12 studies (n = 254,908 patients) were included. For our second comparison, six studies (n = 109,609 patients) were included. Major bleeding events in the underweight group were higher than normal weight [RR: 1.89 (1.10, 3.23); P = 0.02; I² = 0%]. Overweight patients were related with reduced rates of VTE than in patients with normal BMI [RR: 0.86 (0.76, 0.97); P = 0.02; I² = 0%]. In comparison with patients receiving warfarin, DOACs had significantly reduced risk of major bleeding in normal weight, overweight and obese [OR: 0.64 (0.49, 0.83); P = 0.0007 I² = 90%].

Conclusion

The risk of VTE reduces with an increasing BMI, hence there could be a possible obesity paradox in patients with anticoagulation therapy. In comparison to warfarin, DOACs proved to be the safer option by having a reduced risk of bleeding across all BMI categories.

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Warfarin therapy and its effectiveness for prevention of thromboembolism.

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Effect of warfarin and DOACs over different BMI ranges.

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Safety and efficacy of DOACs across different BMI ranges.

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Lower risk of bleeding in normal weight, overweight, and obese patients with DOACs.

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Warfarin and DOACs across different BMI categories in VTE and AF patients.

Clinical outcomes of dabigatran use in patients with non-valvular atrial fibrillation and weight >120 kg

BACKGROUND

Patients with obesity were underrepresented in studies evaluating the safety and effectiveness of direct oral anticoagulants (DOAC) in patients with non-valvular atrial fibrillation (NVAF). This study compared clinical outcomes in patients with NVAF and weighing >120 kg and ≤120 kg who were receiving dabigatran.

MATERIALS AND METHODS

This retrospective, matched, longitudinal cohort study included patients from three integrated healthcare delivery systems. Patients ≥18 years of age with NVAF were included if between September 1, 2016 and June 30, 2019 they received dabigatran. Patients >120 kg and ≤120 kg were matched up to 1:6 on age, sex, and CHA₂DS₂-VASc score. Data were extracted from administrative databases. The primary outcome was a composite of ischemic stroke, clinically-relevant bleeding, systemic embolism, and all-cause mortality. Multivariable regression analyses were performed.

RESULTS

777 and 3522 patients >120 kg and ≤120 kg, respectively, were matched. The >120 kg group tended to be younger with a higher burden of chronic disease. There was no difference between groups in the composite outcome (adjusted hazard ratio [AHR] 1.10, 95% confidence interval 0.89-1.37) or individual components of the composite. A subanalysis of clinically-relevant bleeding identified that patients >120 kg were at a greater risk of gastrointestinal bleeding (AHR 1.44, 95% CI 1.01-2.05).

CONCLUSIONS

In patients with NVAF and >120 kg, dabigatran use was associated with a small increased risk of gastrointestinal bleeding but no differences in stroke, mortality or clinically-relevant bleeding. These findings suggest that dabigatran use is reasonable in patients with NVAF and weight >120 kg.

Body Mass Index Influence on the Clinical Outcomes for Nonvalvular Atrial Fibrillation Patients Admitted to a Hospital Treated with Direct Oral Anticoagulants: A Retrospective Cohort Study

BACKGROUND

Considering that the current fixed dose of direct oral anticoagulants (DOACs) might have insufficient anticoagulation effect for overweight patients, the aim of this study was to compare the effectiveness and safety of anticoagulation between dabigatran and rivaroxaban in different body mass index (BMI) population.

METHODS

We conducted a retrospective cohort study of 2402 DOAC anticoagulated patients with atrial fibrillation who underwent catheter ablation (1290 dabigatran, 53.7% and 1112 rivaroxaban, 46.3%) between January 2017 and December 2018. Patients were distributed based on the BMI into nonobese (1362, BMI <25 kg/m2), preobese (521, BMI 25.0-29.9 kg/m2), class I obese (344, BMI 30.0-34.9 kg/m2) and class II+ obese (175, BMI ≥35.0 kg/m2). We collected information regarding clinical features, laboratory data, bleeding complications and systemic embolic events from the electrical medical records system during 12 months.

RESULTS

The incidence of systemic embolism and stroke complications was higher in the class II+ obese group (P=0.001 and P=0.003). The incidence of bleeding complications and the levels of anticoagulation parameters under the bleeding threshold were similar among the four groups (P>0.05). Cumulative Kaplan-Meier analysis illustrated that rivaroxaban-treated patients who belonged to higher BMI subgroups were more likely to experience shorter time to thrombosis (TTT) (12-month TTT rates of 0.5% for nonobese vs 1.7% for class I obese patients, HR=3.716, P=0.005; 12-month TTT rates of 0.5%, for nonobese vs 4.0% for class II+ obese patients, HR=6.843, P=0.001). However, no statistical significant difference in terms of the time to bleeding complications and the time to cumulative events among the four groups was observed. By multivariate analysis, a higher BMI value (BMI ≥25 kg/m2) (P=0.019; OR=2.094, 95%CI: 1.129-3.883) was an independent predictor for thrombosis in patients treated with dabigatran or rivaroxaban. Positive linear relationship was observed between BMI levels and occurrence rate of thrombosis and bleeding in under anticoagulation patients with NVAF (R2=0.451 and R2=0.383, respectively).

CONCLUSION

The fixed dose of 15 mg rivaroxaban might carry a risk of under exposure, which would lead to an increase of thromboembolic complications in patients with high BMI. Therefore, rivaroxaban dose increase was suggested for obese patients. Use of DOACs appears to have considerable safety in obese patients.

The impact of underweight and obesity on outcomes in anticoagulated patients with atrial fibrillation: A systematic review and meta-analysis on the obesity paradox

Although obesity is associated with the development and progression of atrial fibrillation (AF), an obesity paradox may be present, illustrated by seemingly protective effects of obesity on AF-related outcomes. Body mass index (BMI) has an impact on outcomes in AF patients using oral anticoagulants. After searching Medline and Embase, meta-analysis of results of four randomized and five observational studies demonstrated significantly lower risks of stroke or systemic embolism (RR 0.80, 95%CI [0.73-0.87]; RR 0.63, 95%CI [0.57-0.70]; and RR 0.42, 95%CI [0.31-0.57], respectively) and all-cause mortality (RR 0.73, 95%CI [0.64-0.83]; RR 0.61, 95%CI [0.52-0.71]; and RR 0.56, 95%CI [0.47-0.66], respectively) in overweight, obese and morbidly obese anticoagulated AF patients (BMI 25 to <30, ≥30 and ≥40 kg/m2 , respectively) compared to normal BMI anticoagulated AF patients (BMI 18.5 to <25 kg/m2 ). In contrast, thromboembolic (RR 1.92, 95%CI [1.28-2.90]) and mortality (RR 3.57, 95%CI [2.50-5.11]) risks were significantly increased in underweight anticoagulated AF patients (BMI <18.5 kg/m2 ). In overweight and obese anticoagulated AF patients, the risks of major bleeding (RR 0.86, 95%CI [0.76-0.99]; and RR 0.88, 95%CI [0.79-0.98], respectively) and intracranial bleeding (RR 0.75, 95%CI [0.58-0.97]; and RR 0.57, 95%CI [0.40-0.80], respectively) were also significantly lower compared to normal BMI patients, while similar risks were observed in underweight and morbidly obese patients. This meta-analysis demonstrated lower thromboembolic and mortality risks with increasing BMI. However, as this paradox was driven by results from randomized studies, while observational studies rendered more conflicting results, these seemingly protective effects should still be interpreted with caution.

Efficacy and safety of direct oral anticoagulant in morbidly obese patients with atrial fibrillation: systematic review and meta-analysis

AIMS

We conducted a systematic review and meta-analysis on 3 outcomes. We assessed the efficacy and safety of direct oral anticoagulants (DOAC) compared to vitamin K antagonists (VKA) in morbidly obese patients with atrial fibrillation (AF). We compared the efficacy and safety of DOAC in obese patients and non-obese patients with AF. Finally, we updated the current knowledge of outcomes of AF patients with obesity compared to normal-weight patients regardless of anticoagulation type.

METHODS AND RESULTS

Using PubMed and Embase, we searched for literature published from inception to August 2020 for studies conducted in morbidly obese patients with AF who used DOACs and/or VKA for stroke or systemic embolism (stroke/SE) prevention that report efficacy and/or safety data. GRADE assessment was performed to determine the quality of the meta-analysis results. DOAC was not statistically different from VKA in reducing stroke/SE with RR of 0.85 (95%CI: 0.56 to 1.29; very low certainty evidence). Major bleeding risk was lower in the DOAC groups with RR of 0.62 (95%CI: 0.48 to 0.80; low certainty evidence). Obese patients with AF who used DOACs had lower risk of stroke/SE and similar major bleeding risk compared to nonobese patients with RR of 0.77 (95%CI: 0.70 to 0.84; low certainty evidence) and 1.02 (95%CI: 0.94 to 1.09; low certainty evidence), respectively. Obese patients with AF who used any type of anticoagulant had lower risk of stroke/SE compared to normal-weight patients with RR of 0.62 (95%CI: 0.57 to 0.69; low certainty evidence).

CONCLUSIONS

The use of DOACs in morbidly obese patients maybe reasonable if needed, but more dedicated studies are needed to make a more robust recommendation.

Safety and Efficacy of Rivaroxaban and Apixaban in Patients with Increased Body Mass: a Systematic Review

BACKGROUND AND OBJECTIVE

Rivaroxaban and apixaban are direct oral anticoagulants increasing in popularity as convenient alternatives to warfarin. However, current guidelines recommend against use in patients with a BMI > 40 kg/m² or bodyweight > 120 kg unless drug-specific levels are measured, which may not be feasible across all clinical practices. Accordingly, the objective of this study was to broadly examine literature evaluating the clinical outcomes of rivaroxaban and/or apixaban in patients with increased body mass.

METHODS

A systematic literature review (guided by PRISMA) was performed through January 27, 2021 using PubMed, Embase, and Scopus. Key search term clusters included drug and weight-related concepts (overweight/obese, body mass index [BMI], waist circumference). DistillerSR was utilized to review and process search results. Studies met inclusion if they analyzed the risk of bleeding and/or thrombosis in patients with increased body mass (i.e., via BMI or other criteria) receiving rivaroxaban or apixaban. Clinical guidelines, case reports/series, pharmacokinetic/dynamic analyses, and commentaries were excluded. Bias was examined qualitatively across studies.

RESULTS

After duplicates were removed, the original search rendered 1822 abstracts and 200 full-texts for screening, ultimately providing a final set of 24 studies for qualitative review. Of these studies, 13 (54.2%) enabled comparisons between patients of increased versus normal body mass, while 11 (45.8%) reported outcomes only for patients of increased body mass. The working definition of 'increased body mass' varied amongst the studies, including 11 (45.8%) studies that utilized BMI, seven (29.2%) with a combination of BMI and body measurement, two (8.3%) that relied on body weight alone, and four (16.7%) that identified obesity-related ICD codes. All 13 comparative studies found similar or reduced rates of safety and efficacy outcomes with rivaroxaban and apixaban.

CONCLUSION

The literature reports similar or lower bleeding and thrombotic risk for rivaroxaban and apixaban in patients of increased body mass compared to patients of normal body mass. Future prospective controlled studies are needed to further define guidelines for use in this population.